Conventional parachutes include canopies that can have different shapes and can be made of different materials, as well as suspension lines with a user's harness pending therefrom.
Preinflatable parachutes are equipped with inflatable flexible tube structures of different shapes which are connected to the canopy and can be folded and preinflated with gas in such a way that they accumulate potential energy and perform like springs when retaining devices which keep them folded are released, and consequently expand the canopy almost instantaneously at the beginning of the jump. Please refer to U.S. Pat. No. 4,105,173.